Sampling system and method

Abstract

The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

We claim: 
     
       1. A sampling method comprising, in a downhole environment:
 obtaining a fluid sample; 
 pumping the fluid sample from a first positive displacement pump to a reservoir operatively coupled to a positive displacement staging pump, the reservoir being open to the atmosphere; 
 pumping the fluid sample from the reservoir with the staging pump to a collection vessel; and 
 controlling the flow rates of the first positive displacement pump and the positive displacement staging pump to avoid cavitation of the positive displacement staging pump. 
 
     
     
       2. The sampling method of  claim 1 , wherein the positive displacement staging pump and reservoir are part of a staging pump assembly, the staging pump assembly comprising a housing surrounding the positive displacement staging pump and the reservoir. 
     
     
       3. The sampling method of  claim 1 , further comprising coupling the positive displacement staging pump to upstream air supply and exhaust tubes and downstream air supply and air exhaust tubes. 
     
     
       4. The sampling method of  claim 3 , wherein coupling the positive displacement staging pump to upstream air supply and exhaust tubes and downstream air supply and air exhaust tubes comprises coupling the air supply and exhaust tubes to manifolds coupled to the positive displacement staging pump. 
     
     
       5. The sampling method of  claim 1 , wherein the positive displacement staging pump is coupled to an upstream tubing bundle and a downstream tubing bundle. 
     
     
       6. The sampling method of  claim 5 , further comprising deploying a wireline proximate the upstream and downstream tubing bundles while coupling the wireline to the upstream and downstream tubing bundles. 
     
     
       7. The sampling method of  claim 6 , wherein coupling the wireline to the upstream and downstream tubing bundles comprises attaching the wireline to the tubing bundles with clamps at a plurality of points along the length of the upstream and downstream tubing bundles. 
     
     
       8. A pump assembly comprising:
 a staging pump assembly comprising:
 a housing, the housing defining a reservoir open to the atmosphere; 
 a first positive displacement pump having an air supply inlet, an exhaust air outlet, a sample inlet, and a sample outlet; 
 an air supply manifold coupled to the air supply inlet of the first positive displacement pump; 
 an exhaust air manifold coupled to the exhaust air outlet of the first positive displacement pump; 
 
 an upstream pump assembly comprising a second positive displacement pump having a pump inlet and a pump outlet, the pump outlet coupled to the sample inlet of the first positive displacement pump; and 
 a computing device coupled to the first positive displacement pump and the second positive displacement pump and programmed to synchronize the pump rates of the first displacement pump and the second displacement pump in order to avoid cavitation in the first displacement pump. 
 
     
     
       9. The pump assembly of  claim 8 , further comprising a control valve coupled to the air exhaust manifold. 
     
     
       10. The pump assembly of  claim 8 , further comprising an exhaust bypass tube coupled to the exhaust air manifold. 
     
     
       11. The pump assembly of  claim 8 , further comprising an air supply bypass tube coupled to the air supply manifold. 
     
     
       12. The pump assembly of  claim 8 , wherein the sample inlet is in fluid communication with the interior of the housing. 
     
     
       13. A sample collection system comprising:
 the pump assembly of  claim 8 ; 
 an upper tubing bundle; 
 a lower tubing bundle; 
 a wireline; and 
 a plurality of clamps coupled to the upper tubing bundle and the wireline. 
 
     
     
       14. The sample collection system of  claim 13 , further comprising a plurality of clamps coupled to the lower tubing bundle and the wireline. 
     
     
       15. The sample collection system of  claim 13 , wherein the upper and lower tubing bundles each comprise an air supply tube, an exhaust air tube, and a sample tube, the air supply tubes coupled to the air supply manifold of the staging pump assembly, the exhaust air tubes coupled to the exhaust air manifold of the staging pump assembly, and the sample tube of the upper tubing bundle coupled to the sample outlet of the first positive displacement pump. 
     
     
       16. The sample collection system of  claim 15 , wherein the sample tube of the lower tubing bundle is fluidly coupled to the sample inlet of the first positive displacement pump. 
     
     
       17. The sample collection system of  claim 15 , wherein the sample tube of the lower tubing bundle is fluidly coupled to a reservoir formed by the housing of the staging pump assembly, the reservoir fluidly coupled to the sample inlet of the first positive displacement pump.